The present invention relates to a rotary control device for a circuit breaker, notably a three-phase circuit breaker of industrial type, this circuit breaker comprising a front closing plate provided with an opening through which there passes a pivoting crank pin able to occupy at least two stable extreme positions, this device comprising a housing mounted on said front plate, a rotary handle securedly united to this housing and a mechanism to couple said handle and said crank pin.
State-of-the-art circuit breakers, and in particular three-phase industrial circuit breakers, are usually housed in cases whose front closing plate comprises an elongated opening through which there passes a pivoting crank pin which can occupy two stable positions corresponding respectively to opening and closing of the circuit breaker, and an intermediate middle position which indicates a fault. These cases are sometimes mounted in an electrical enclosure or switchboard equipped with a door. There exists an accessory which can be fitted on the front plate or on the door of the switchboard and which enables rocking of the crank pin to be controlled by means of a rotary handle. The drawback of state-of-the-art devices of this kind lies in the fact that they do not comprise efficient safety devices enabling assembly to be prevented when the two coupled control means, i.e. the crank pin and the rotary handle, are in disagreement.